The present invention relates to blind rivets and more particularly to a rotatably fastening blind rivet which is tensed by rotating a hexagon fastening rod inside a turbular body manually or mechanically and which provides greater clamp force to prevent the workpiece from becoming break-away or looseness. Besides, it increases the fatigue strength so that the blind rivet will be more durable.
Blind rivet is useful to fasten two or more workpieces together in civil and mechanical engineering or in the high-tech aeronautic engineering which requires highest quality of the blind rivets.
U.S. Pat No. 4,639,174 discloses a self-plugging blind rivet which utilizes the clamp force of the rivet to fasten two or more workpieces together by axially applying pulling force to a stem to force a tubular body to be deformed so as to clamp the workpieces. Because the pulling force is mostly consumed with the displacement of the stem, it could not be totally transferred to the deformation of the tubular body, So it may cause a weak clamp force or poor fatigue strength for the rivet. Further, this blind rivet lacks threads formed between the stem and the tubular body, this also causes an uneven tensioning that the stem may be disconnected with the tubular body after a certain time of use.
U.S. Pat. No. 4,865,499 also discloses a self-plugging blind rivet in which thread is partially formed on a small region of the stem, so that the fastening of this rivet is performed by partially pulling and partially rotation of the stem. This improvement can provide greater clamp force that insures the rivet to be more durable and stabilized. However, it requires a twice operation that is not economical.